39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
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#include <stdio.h>
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#include <stdbool.h>
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#define NUM_PLACES 4
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// 回溯函数：尝试构建所有可能的路径组合，A 总是紧跟 B
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void backtrack(int *path, bool used[NUM_PLACES], int step)
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{
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if (step >= NUM_PLACES)
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{ // 边界条件：当步骤数等于地点数时打印路径
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for (int i = 0; i < NUM_PLACES; ++i)
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printf("%c", 'A' + path[i]);
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printf("\n");
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return;
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}
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// 如果还有足够的空间，尝试放置 A 和 B 作为一对
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if (step + 1 < NUM_PLACES && !used[0] && !used[1]) {
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path[step] = 0; // 放置 A
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path[step + 1] = 1; // 放置 B
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used[0] = used[1] = true;
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backtrack(path, used, step + 2);
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used[0] = used[1] = false;
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}
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// 尝试放置 C 或 D
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for (int i = 2; i < NUM_PLACES; ++i) {
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if (!used[i]) {
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path[step] = i;
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used[i] = true;
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backtrack(path, used, step + 1);
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used[i] = false;
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}
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}
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}
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int main(){
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int path[NUM_PLACES];
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bool used[NUM_PLACES] = {false};
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// 开始回溯，从一个空路径开始
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backtrack(path, used, 0);
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return 0;
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}
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